Theodore g



Patented May I6, |899.

T. s. LEwls.

DENTAL PLUGGER. h

(Application file d Aug. 11, 189B.)

(No Model.)

IlNiTnD STATES PATENT OFFICE.

THEODORE G. LEWIS, OF BUFFALO, NEW YORK, ASSIGNOR TO TI-IE BUFFALODENTAL MANUFACTURING COMPANY, OF SAME PLACE.

DENTAL PLUGGER.

SPECIFICATION forming part of Letters Patent No. 625,043, dated May 16,1899. Application tiled August 11, 1898. Serial No. 688,349. (No model.)

f falo, in the county of Erie and State of New York, have invented newand useful Improvements in Dental Pluggers, of which the following is aspecification.

This invention relates to a dental plugger in which the tool-shan k isstruck by a springpropelled hammer and in which the parts are organizedto produce a long or short stroke of the hammer. 1

The objects of this invention are to improve the means of varying thestroke of the hammer, to improve the supports of the hammerspring, toimprove the support of the shankspring, and to simplify and improve thecatchplate of the hammer. l Y

In the accompanying drawings, Figure l is a longitudinal section of myimproved dental plugger on an enlarged scale, showing the i parts adjusted for producing a long stroke of the hammer. Fig. 2 is a fragmentaryoutside View of the upper or rear end of the plugger. Fig. 3 is adetached view of the hammerspring and connecting parts. Fig. 4t is afragmentary longitudinal section, on a still further enlarged scale, ofthe tool shank or plunger and the stop collar mounted thereon. Fig. 5 isa cross-section thereof in line 5 5,

Fig. 4. Fig. 6 is a cross-section, on an enlarged scale, in line 6 6,Fig. l. Fig. 7 is a perspective view of the hammer. Fig. 8 is a detachedperspective view of the catch-plate. Fig. 9 is a fragmentarylongitudinal section of the throw-adjusting4 mechanism, showing theparts adjusted for produ cinga short throw of the hammer.

Like letters of reference refer to like parts in the several figures.

The inclosing case of the plugger consists of an upper or rear section Aand a lower or front section A', which is screwed into the uppersection, each section being preferably provided with a covering a. ofrubber.

B represents the longitudinally-movable shank or plunger, which carriesthe pluggertool h at its lower or front end. This shank is arranged withits central portion in the lower case-section A', while its upper'orrear end projects into the upper section of the case.

C represents the.longitudinally-movable ,l

hammer, which is arranged in the upper section of the case and which isadapted to strike the upper end of the tool-shank. The lower end of thehammer, which strikes the shank,

is preferably provided with a rubber plug c d2 in the shank, in `whichthe collar is secured, Figs. l, 4, and 5. The collarV is split on oneside and sprung into this groove and soldered 'in place.

E represents a nipple which is screwed into the lower end of the lowercase-section.

F represents an adjustable stop-sleeve, whereby the outward movement ofthe shank and the stroke of the hammer maybe varied. This sleevesurrounds the lower portion of the tool-shank and. is provided with anexternal screw-thread, which engages with an internal screw-thread inthe nipple. The inner end of the stop-sleeve serves as an abutmentagainst which the collar d on the shank strikes and whereby the' forwardor projecting movement of the shankis arrested. This collar thus servesthe double purpose of receiving the thrust of the shank-spring andlimiting'the forward movement of the shank.

Upon turning the adjusting-sleeve in one or the other direction it moveslengthwise in the nipple and shifts the inner abutment or stop end ofthe sleeve inwardlygor outwardly, thereby varying the outward movementof the shank. The longitudinal movement of the adjusting-sleeve islimited by an outer stop f, Figs. I and 9, which is adapted to engagewith the outer end of thenipple upon screwing the sleeve inwardly, andby an inner stop f', which is adapted to engage with the inner end ofthe nipple upon screwing the adjusting-sleeve outwardly. The outery stopf consists, preferably, of an annular flange which is formed integrallywith the adjusting- IOO sleeve, and the inner stop consists of aninternally-screw-threaded collar which is screwed upon theexternally-screw-threaded inner end of the adjusting-sleeve. Inassembling the parts the inner stop f' is shifted lengthwise on thesleeve for adjusting the extent of the longitudinal movement of thesleeve and is then permanently secured to the sleeve, preferably bysoldering, in order to prevent the stop from becoming displaced.

G represents the hammer-spring, arranged with its lower portion in theupper case-section and with its upper portion in an adjusting-cap H,screwed into the upper end of the upper case-section. The lowermost coilh of the hammer-springis contracted and clamped firmly around thereduced upper end or stem c of the hammer, and the uppermost coil h' isalso contracted and clamped firmly around the depending stud t' of acircular button I. The latter is provided with a rounded or convex backor upper side '11', which is seated in a corresponding concave seat 2 inthe upper portion of the adjusting-cap, as shown in Fig. l. rlheintermediate or body portion of the hammer-spring is larger in diameterthan its end portions and smaller in diameter than the surroundingcasing, so that the body of the spring is out of contact with theadjacent parts of the plugger, thereby preventing the spring fromscraping against these parts. The spring is maintained in this positionby the coperating convex and concave faces of the button and cap, whichserve to center the spring in the plugger. By lirmly holding the springat its ends and leaving the intermediate portion free the singing noise,which is produced by a spring having its ends unsecured, is avoided. Thedownward movement of the hammer is limited by a stop or featherj,secured to the inner side of the upper casesection below the hammer, asshown in Fig. l. The blow of the hammer may be regulated by screwing thecap H in or out, and so varying the tension of the hammer-spring, theforce of the blow being readily determined by the graduations 7c on theouter side of the cap, as

shown in Fig. 2. By interposing between the upper end of thehammer-spring and the adjusting-cap a button on which the adjustingcapcan turn the noise, which otherwise would be produced by the scraping ofthe end of the spring against the cap during adjustment, is avoided.

L represents the usual latch whereby the hammer is retracted and the hammer-springis compressed and which is arranged lengthwise with its upperend in a longitudinal groove l, formed in the side of the hammer. Thelower end of t-he latch is arrangedin anotch Z,which is formed in a headm, secured to the upper end of the tool-shank, and is provided with alaterally projecting toe Z2, which engages looselyin a transverseopeningm iu the shank. The upper end of the latch is provided on itsinner side with the usual shoulder Z3,which is adapted to engage eitherone of two shoulders n n,which are arranged one above the other on acatch-plate N, mounted on the hammer. This plate has the form of adovetail with the shoulders arranged on the wide portion thereof and isfitted into a correspondingly-shaped groove o,which is formedtransversely in the hammer and intersects the catch-groove Z at rightangles. The ends of the catch-plate are rounded off {iush with thehammer, as shown at o', Fig. 6, and bear against the inner side of theupper case-section, thereby confining the catch-plate in its groove.

By forming both catch-shoulders on one plate the construction issimplified, the strength of the catch is increased, and the cost ofproducing the same is reduced.

By arranging the catch-shoulders on the wide side of the catch-plate thelower or front edge of the plate may be utilized as the lower or frontshoulder n and requires only the upper or rear shoulder n to be cut intothe catchplate,whereas if the shoulders were arranged on the narrow sideof the catch-plate both shoulders would have tobe cut into the same.

P represents the usual trip shoe or cam with which the upper end of thelatch engagesduring the last portion of the upward movement of thehammer, and whereby the latch is released from the catch-plate to permitthe hammer to descend or move forward and deliver the blow against thetool-shank. The tripshoe is secured in the usual manner to the innerside of the upper case-section within the latch-groove l. The latch isyieldingly pressed inwardly by a spring Z4, so that its shoulder is inline with those of the catch-plate.

In the position of the parts represented in Figi the adj usting-sleeveis moved outwardly to its fullest extent forproducingalong throw orstroke of the hammer, the tool-shank is projected and bears with itscollar d against the inner end of the adjusting-sleeve, and the hammeris in its foremost position with its front catch-shoulder n facing theshoulder of the latch. Upon placing the end of the tool against thetooth-filling to be plugged and then moving the case forwardly on thetoolshank the latch engages its shoulder with the front or lowercatch-shoulder of the hammer and stops the hammer and causes thehammer-spring to be compressed.

When it desired to obtain a short stroke of Y placing the tool against afilling and moving the case forwardly when the parts are in thisposition the hammer is operated by the engagement of the uppercatch-shoulder with that of the latch, and the latter being now nearerto the trip-cam than when it is in its lowest position the latch isreleasedsooner IOC IOE

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from the hammer and a shorter stroke of the hammer is produced.

In the use of my improved adjusting device for changing the length ofstroke of the hammer it is only necessary to screw the ad#justing-sleeve inwardly or outwardly as far as possible. The extent ofthis movement is controlled by the outer and inner stops ff' on theadjusting-sleeve, and When this sleeve is shiftedlto either extreme ofits longitudinal movement the shoulder of the latch stands normallyopposite one or the other shoulder of the catch-plate and produces ashort or long stroke of the hammer. The change from a a short stroke toa long stroke, or vice versa, is easily and conveniently effected by theoperator Without requiring any particular care, as theadjusting-sleeveis stopped When it has reached the proper position. Theadj ustingsleeve can be screwed sufficiently tight at either extreme ofits longitudinal movement to hold it securely in position.

I claim as my inventionl. The combination With the tool-shank providedwith an annular groove and the stopsleeve surrounding the shank, of asplit collar arranged in the groove of the shank and bearing with oneside against said sleeve, and a spring bearing against'the opposite sideof the collar, substantially as set forth.

2. The combination with the case, the toolshank, the hammer providedWith shoulders at different distances from the shank, and the latchconnected with said shank and adapted to engage with either of theshoulders on'the hammer, of a stop -sleeve surrounding the shank andcapable of longitudinal adjustment for varyin g the stopping position ofthe shank and latch, substantially as set forth.

3. The combination with the case, the-toolshank, the hammer providedWith shoulders at diderent distances from the shank, and the latchconnected with said shank and adapted to engage With either of theshoulders on the hammer, of a stop-sleeve surrounding the tool-shank andhaving an external screwthread Which-engages in a threaded opening inthe case, whereby the sleeve may be shifted lengthwise of the shank forvarying the point at which the forward movement of the shank isarrested, substantially as set forth.

et. The combination With the case, the toolshank, the hammer providedWith shoulders at different distances from the shank, and the latchconnected with said shank and adapted to engage with either of theshoulders on the hammer, of a nipple attached to said case, astop-sleeve arranged in said nipple and adapted to be engaged by ashoulder on said shank, and stops arranged on said sleeve on oppositesides of the nipple, substantially as set forth.

5. The combination with the case, the toolshank, the hammer providedwith shoulders at diderent distances from the shank, and the latchconnected With said shank and adapted to engage with either of theshoulders on the hammer, of an internally-threaded nipple attached tosaid case, a screw-sleeve arranged in said nipple and adapted to beengaged by a shoulder von said shank, a stop-collar arranged on saidsleeve on the outer side of the nipple, and an internally-screW-threadedstopcollar secured to the threaded portion of the sleeve on the innerside of the nipple, substantially as set forth.

G. The combination With the case, the harnmer and the tool-shank, of acap connected with the end of the case and provided with a concave seat,abutton having a convex back engaging with the concave seat of the cap,and a spring connected at one end to the hammer and at its opposite endto said button, substantially as set forth.

7. The combination With the case, the ham mer provided With a stem, andthe tool-shank, of a cap connected Withthe case and provided with aconcave seat, a button provided with a convex back which engages withthe concave seat and having a project-ing stud, and a coil-spring havingits body out of contact with the case and having its end coilscontracted and secured respectively to the stem of the hammer and thestud of the button, substantially as set forth. l

8. The combination with the tool-shank provided with a latch, of ahammer having a longitudinal groove and a dovetail groove arrangedacross said latch-groove, and a` dove# tail catch-plate arranged in saiddovetail groove across said latch-groove, substantially as set forth.

9. The combination with the toolshank provided with a latch, of a hammerhaving a longitudinal latch groove and a dovetail groove arranged acrosssaid latch-groove, and a dovetail catch-plate arranged in said dovetailgroove across said latch-groove and provided in its side with shoulders,one above the other, for engagement with said latch, substantially asset forth.

Witness my hand this 9th day of August,

THEODORE G. LEWIS.- Vitnesses:

JNO. J. BoNNnR, ELLA R. DEAN.

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